1. Technical Field
The present invention relates to a motion analysis method, a program, and a motion analysis device which analyze the motion of a user.
2. Related Art
JP-A-2009-20897 discloses a technology that performs display by photographing a golf swing motion using a camera or the like from the back of a user, specifying a swing plane from a photographed image, displaying the swing plane, and measuring the area of the swing plane. The swing plane is a plane in which a line segment including an arm, a club shaft, and a club head (or a club shaft and a club head) moves during a golf swing motion and remains as a locus. Generally, when viewed from the back of the swing, it is determined that swing is good if the swing plane does not have an area as much as possible and is close to a segment. Accordingly, according to the technology of JP-A-2009-20897, the user is capable of quantitatively knowing whether the swing is good or bad from information of the area of the swing plane.
However, even when the area of the swing plane is small, there is a case in which the user hits a hook or a slice according to a swing path, and thus the small area of the swing plane is not necessarily a good swing. Here, when directing golf swing, there is a case in which indexes, such as a shaft plane and a hogan plane, are used. The shaft plane is a plane that includes the longitudinal direction of the shaft of a golf club at address (standstill state) in golf and a target line (ball-hitting direction), and the hogan plane is a plane that includes a virtual line, which connects the peripheries of the shoulder (the joint or the like of the shoulder and the neck) of a golfer at address in golf and the head of the golf club (or a ball), and a target line (target ball-hitting direction). A region which is interposed by the shaft plane and the hogan plane is called a V zone, and it is known that the user hits a straight if the locus of the golf club is included in the V zone when down swing is performed. Accordingly, it is possible to evaluate good or bad of swing based on whether or not the locus of the golf club is included in the V zone when down swing is performed. However, a technology that accurately presents the shaft plane and the hogan plane to the user has not been proposed yet.